From: boris.brezillon@free-electrons.com (Boris Brezillon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 08/14] pwm: sti: Avoid glitches on already running PWMs
Date: Tue, 14 Jun 2016 11:13:16 +0200 [thread overview]
Message-ID: <1465895602-31008-9-git-send-email-boris.brezillon@free-electrons.com> (raw)
In-Reply-To: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com>
The current logic will disable the PWM clk even if a PWM was left
enabled by the bootloader (because it's controlling a critical device
like a regulator for example).
Keep the PWM clk enabled if at least one PWM is enabled to avoid any
glitches.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/pwm/pwm-sti.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
index 6300d3e..5bda51d 100644
--- a/drivers/pwm/pwm-sti.c
+++ b/drivers/pwm/pwm-sti.c
@@ -340,7 +340,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
struct sti_pwm_compat_data *cdata;
struct sti_pwm_chip *pc;
struct resource *res;
- int ret;
+ int i, ret;
pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
@@ -391,7 +391,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
return -EINVAL;
}
- ret = clk_prepare(pc->clk);
+ ret = clk_prepare_enable(pc->clk);
if (ret) {
dev_err(dev, "failed to prepare clock\n");
return ret;
@@ -409,6 +409,16 @@ static int sti_pwm_probe(struct platform_device *pdev)
return ret;
}
+ /*
+ * Keep the PWM clk enabled if some PWMs appear to be up and
+ * running.
+ */
+ for (i = 0; i < pc->chip.npwm; i++) {
+ if (pwm_is_enabled(&pc->chip.pwms[i]))
+ clk_enable(pc->clk);
+ }
+ clk_disable(pc->clk);
+
platform_set_drvdata(pdev, pc);
return 0;
--
2.7.4
next prev parent reply other threads:[~2016-06-14 9:13 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-14 9:13 [PATCH v3 00/14] regulator: pwm: various improvements Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 01/14] pwm: Add an helper to prepare a new PWM state Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 02/14] pwm: Add two helpers to ease relative duty cycle manipulation Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 03/14] pwm: rockchip: Fix period and duty_cycle approximation Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 04/14] pwm: rockchip: Add support for hardware readout Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 05/14] pwm: rockchip: Avoid glitches on already running PWMs Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 06/14] pwm: rockchip: Add support for atomic update Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 07/14] pwm: sti: Add support for hardware readout Boris Brezillon
2016-06-14 9:13 ` Boris Brezillon [this message]
2016-06-14 9:13 ` [PATCH v3 09/14] regulator: pwm: Adjust PWM config at probe time Boris Brezillon
2016-06-14 9:13 ` [PATCH v3 10/14] regulator: pwm: Switch to the atomic PWM API Boris Brezillon
2016-07-05 14:30 ` Mark Brown
2016-06-14 9:13 ` [PATCH v3 11/14] regulator: pwm: Properly initialize the ->state field Boris Brezillon
2016-07-05 14:31 ` Mark Brown
2016-06-14 9:13 ` [PATCH v3 12/14] regulator: pwm: Retrieve correct voltage Boris Brezillon
2016-07-05 14:32 ` Mark Brown
2016-07-08 15:43 ` Thierry Reding
2016-07-09 9:47 ` Mark Brown
2016-07-11 7:02 ` Thierry Reding
2016-07-11 7:20 ` Boris Brezillon
2016-07-11 16:53 ` Doug Anderson
2016-06-14 9:13 ` [PATCH v3 13/14] regulator: pwm: Support extra continuous mode cases Boris Brezillon
2016-07-05 14:34 ` Mark Brown
2016-06-14 9:13 ` [PATCH v3 14/14] regulator: pwm: Document pwm-dutycycle-unit and pwm-dutycycle-range Boris Brezillon
2016-06-16 22:26 ` Rob Herring
2016-07-05 14:36 ` Mark Brown
2016-07-08 16:35 ` [PATCH v3 00/14] regulator: pwm: various improvements Thierry Reding
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